1. Excretory System By: Your wonderful teacher for a day… Cynthia Castillo(:

3. Insects &other animals w/ open circulatory have internal “pond” mad of hemolymph = bathes all body cells

4. Vertebrates &other animals w/ closed circulatory have internal pond(interstitial fluid) that is serviced by blood

5. Animals w/ closed circulatory system have three internal fluid compartments:

6. Intracellular component-consists of the cytosol of cells

7. Two extracellular compartment:

8. Blood plasma and interstitial fluid

9. Homeostasis enables animals to survive changes (temp.) in environment by tempering changes in body fluids

11. Convection- transfer of heat by the movement of air or liquid past a surface

12. Radiation- the emission of electromagnetic waves by all objects warmer than absolute zero, including the animal’s body, the environment, and the sun

14. Four general categories of adaptations help animals thermoregulate: Adjusting the rate of heat exchange btwn the animal and its surroundings. Vasodilation- increase in the diameter of superficial blood vessels triggered by nerve signals that relax the muscles of the vessel walls. In Endotherms, vasodilation usually warms the skin, increasing the transfer of body heat to cool environment by radiation, conduction, and convection Vasoconstriction- (reverse process) reduces blood flow and heat transfer by decreasing the diameter of superficial vessels Countercurrent heat exchanger- helps trap heat in the body core and is important in reducing heat loss in many endotherms.

15. Cont. 2. Cooling by evaporative heat loss Terrestrial animals lose water by evaporation from the skin and when they breathe Water absorbs heat when evaporates (Sweating or bathing also enhances evaporative cooling) 3. Behavioral responses Changes in posture or movement Hibernation or migration to a more suitable climate 4. Changing the rate of metabolic heat production Only endotherms(mammals&birds) Increase metabolic heat production when exposed to cold

17. Osmoconformers=isotonic w/ aqueous surroundings do not regulate their osmolarity

18. Osmoregulators=control water uptake and loss in a hypertonic or hypotonic environment; enables animals to live

19. All freshwater &marine = maintain an internal osmolarity that differs from the surrounding water

20. Humans &other terrestrail animals= compensate for water loss

21. Stenohaline=animals that cannot tolerate substantial changes in external osmolarity

25. Osmolarity of internal fluid higher than surroundingsex. fishes-bail out water by excreting large amounts of very dilute urine&regaining lost salts in food or by active uptake from their surroundings

27. Ex. Humans-die if lose 12% of body water

28. Dessication= most important problem confronting terrestrial life (plant & animal)

29. Combat dessication by:

30. Drinking & eating food w/ high water content

31. Nervous & hormonal control of thirst

32. Behavioral adaptations

35. Flatworms

36. Simple tubular excretory system

38. Metanephridium=internal openings that collect body fluids

39. Metaphridia found in annelids (Earthworms)

40. Each segment of worm includes Meta.

41. tubules immersed in coelomic fluid &enveloped by a lot of capillaries

42. Has excretory & osmoregulatory functions

44. Remove nitrogenous wastes from the hemolymph; function in osmoregulation

47. Collecting duct (permeable to water but not to salt) carries filtrate through kidney’s osmolarity gradient and more water exits by osmosis.

48. Urea diffuses out of tubule with salt and forms osmotic gradient that enables the kidney to make urine that is hyperosmotic to blood

49. Osmolarity of urine regulated by nervous system and hormonal control of water and salt reabsorption